Displaying 1 result from an estimated 1 matches for "before_eom".
2006 Sep 04
1
how to fit gauss beam?
Hello,
I am having a hard time fitting a gauss beam using R. In
gnutplot I did something like
$ w(z) = w0 * sqrt(1+(z/z0)**2)
$ fit w(z) 'before_eom.txt' using 1:2 via w0, z0
to obtain w0 and z0. Now I want to do the same in R. I tried
a linear model like this (r = radius, z = distance):
beam <- function(z) {
sum(sqrt(1 + z**2))
}
lm(r ~ I(beam(z)), data = before_eom)
Which gives nonsensical answers ...
Then I tried a nonlinear m...